OK Galaxy, here ya go.... this is straight out of the Ford service manual. Pay special attention to the TFT sensor section. This is exactly what We are talking about. It is there, it is not imaginary, and it works just as described. Within a mile or so the fluid should be warm enough to allow the torque converter to lock up, then if your pulling hard or up a grade it might even shift into OD. If it's flat ground and there is little load on the truck it WILL take longer. THis is from another post on this site by a person that is a Ford tech.

Everthing that controls the trans , I edited some , heres the main ones. -

The following provides a brief description of each of the sensors and actuators used to control transmission operation.

Mass Air Flow (MAF) Sensor

The mass air flow sensor (MAF) measures the mass of air flowing into the engine. The MAF sensor output signal is used by the powertrain control module (PCM) to calculate injector pulse width. For transmission strategies the MAF sensor is used to regulate electronic pressure control EPC, shift and torque converter clutch scheduling.

Output Shaft Speed (OSS) Sensor

The output shaft speed (OSS) sensor is a magnetic pickup, located at the output shaft ring gear, that sends a signal to the powertrain control module to indicate transmission output shaft speed. The OSS is used for torque converter clutch control, shift scheduling and to determine electronic pressure control.

Digital Transmission Range (TR) Sensor

The digital transmission range (TR) sensor is located on the outside of the transmission at the manual lever. The digital TR sensor completes the start circuit in PARK and NEUTRAL, the back-up lamp circuit in REVERSE and the neutral sense circuit (4x4 only) in NEUTRAL. The digital TR sensor also opens and closes a set of four switches that are monitored by the powertrain control module (PCM) to determine the position of the manual lever (P, R, N, D, 2, 1).

Transmission Fluid Temperature (TFT) Sensor

The transmission fluid temperature (TFT) sensor is located on the lead frame assembly near the shift solenoids on the main control valve body. It is a temperature sensitive device called a thermistor. It sends a voltage signal to the PCM. The voltage signal varies with transmission fluid temperature. The PCM uses this signal to determine whether a cold start shift schedule is necessary. The shift schedule is compensated when the transmission fluid temperature is cold. The PCM also inhibits (TCC) operation at low transmission fluid temperatures and corrects electronic pressure control.

Vehicle Speed Sensor (VSS)

The vehicle speed sensor (VSS) is model dependent. Possible sources of vehicle speed input are, anti-lock brake sensor (ABS), a gear-driven vehicle speed sensor (VSS), or the transmission output shaft speed (OSS) sensor. On 4x4 applications with a manual shift transfer case, the transfer case speed sensor is the source of vehicle speed. The VSS signal is either an AC signal whose frequency changes with vehicle speed, or an SCP data message depending on the source. Some vehicles have both. The vehicle speed signal is an input to various vehicle sub-systems such as the powertrain control module (PCM), instrument cluster (speedometer and odometer), speed control systems, etc. The vehicle speed source must be operational to enter output state control mode for diagnostics.

Electronic Pressure Control (EPC) Solenoid

The electronic pressure control (EPC) solenoid regulates transmission pressure. EPC valve pressure is used to control line pressure.

Torque Converter Clutch (TCC) Solenoid

The torque converter clutch (TCC) solenoid is used to control the apply and release of the TCC.

Throttle Position (TP) Sensor

The throttle position (TP) sensor is a potentiometer mounted on the throttle body. The TP sensor detects the position of the throttle plate and sends this information to the powertrain control module (PCM). The TP sensor is used for shift scheduling, electronic pressure control and torque converter clutch (TCC) control.

 

WOW!!! Great write up, thanks. Like I said before, wasn't trying to argue...sincerely! I guess different conditions just add up and the tranny does what it needs to.

 

And... with a deep pan and large cooler, it takes longer yet to heat the fluid, and even to stabilizing overall temp from a cold start.
Once heated, the deep pan dosn't do a whole lot to keep 'overall' temp down anywhere except in the pan area where sleightly more surface area cooling takes place on the larger volume, while moving..

 

My dads truck (the one referenced in my last post) is completely stock. I guess what I've been trying to say is I don't doubt for a single second that all these things, including some temp, influence tranny operation and how/when it shifts. I just doubt the accuracy of not shifting into O/D until a fluid temp of 90*. Your comment here further proves or supports my theory that this particuar temp is not accurate, at least on my truck. If 90* was accurate, my truck (especially with the new cooler) would never shift into O/D.

 

I keep hearing about how you have to keep the torque converter locked to keep it cool, but isn't the locking and unlocking automatic? I've never seen a switch that will lock it. But I guess I haven't looked my 2005 over that well yet.

My brother-in-laws Titan has a tow mode switch which I assume is a lock for the converter. Also our GMC's at work have a tow mode button in the shifter which might be a lockup too.

 

There's no switch or selector on the Fords to keep it locked. You can somewhat control it however with the gas pedal. It comes down to throttle control and learning what your truck wants and how it drives. It is a completely automatic function though like you said, just a little manipulation is all it takes to convince it otherwise. Something you and your truck will have to learn together.

 

I wonder if there is a way to wire it up? If other manufacturers have a button then it must be controlled by a solenoid or some other kind of actuating device on their vehicles. Maybe Ford does the same thing.

 

There is a way to wire a switch to control converter lock up.
Been done already on a Ford.
PCM supplies voltage on a seperate lead thru the harness to the plug on the side.
A tranfer switch to take control away from the PCM and to your supplied voltage will do the job.
You need to understand that with lockup forced on, there are several circumstances that can happen if your not on the ball with the switch.
One is the motor will try to keep driving the truck in an emergency situation with the forced application on. As it is now, the converter auto unlocks when you lift the throttle so reduced brake reaction time is possible.
Another is it auto unlocks when coasting to a stop or it will heep trying to move the truck just like a standard manuel trans with the clutch released.
And all the variations one sees, in between.
The treatment is much the same as Cruise Ciontrol. If engaged, it will keep the motor driving the truck unless you either hit the brakes, manuelly turn it off or the speed drops to low.
If you do this, drive with caution and don't forget about it.
Under normal conditions the lockup modulates on and off an unblievable amount during driving and you never really feel it happening.
The converter auto lock EEC/PCM control has been used since at least 1984 with the A4LD and any converter with electric lockup.

 

When I am towing, I use my dashhawk for Tranny temps, coolant, etc. but most invaluable to me so far has been the DT Slip counter which indicates lock up or not. helps me adjust the variables (gear, accelarator position, etc) to keep it at low/zero to help keep tranny temps down. The Edge (it's brother) may have the same counter.